feat(storage): helper functions for new lifecycle action

[coryan]

A new helper function to avoid typos. Also add the snippet for this
feature.

Fixes #8690

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Here is the summary of changes.

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• google/cloud/storage/examples/storage_lifecycle_management_samples.cc:119, tag storage_set_lifecycle_abort_multipart_upload

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For commit: 842d275a6be199637c42cf2cfe4171ea784f2283

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[codecov]

Codecov Report

Merging #9028 (842d275) into main (269a173) will decrease coverage by 0.00%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##             main    #9028      +/-   ##
==========================================
- Coverage   94.47%   94.47%   -0.01%     
==========================================
  Files        1421     1421              
  Lines      125201   125222      +21     
==========================================
+ Hits       118288   118307      +19     
- Misses       6913     6915       +2     

Impacted Files	Coverage Δ
google/cloud/storage/lifecycle_rule.h	99.00% <ø> (ø)
...e/examples/storage_lifecycle_management_samples.cc	94.89% <100.00%> (+1.22%)	⬆️
google/cloud/storage/lifecycle_rule.cc	100.00% <100.00%> (ø)
...le/cloud/internal/default_completion_queue_impl.cc	97.15% <0.00%> (-0.57%)	⬇️
...cloud/pubsub/internal/subscription_session_test.cc	97.75% <0.00%> (-0.25%)	⬇️

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[coryan]

/FYI: @BrennaEpp @shaffeeullah

[shaffeeullah]

Looks good! Thanks @coryan ! Note we're not officially supporting samples for this, but doesn't hurt to have it.